1. Field of the Invention
This invention is directed generally to surveying instruments and, more particularly, to a survey range pole having a detachable battery module.
2. Prior Art
A survey range pole traditionally has been made of aluminum and is carried by one member of a survey party to mark particular reference or measurement points. The range pole is visible at a distance to others in the survey party, so that distances to the range pole can be determined, or ranged. Traditionally, a range pole has a prism or target mounted at its top end.
Modern surveying systems now use global positioning systems (GPS) to determine the longitude, latitude, and altitude of points being surveyed. Previously, GPS receivers had batteries contained within the receiver housing itself or the GPS receivers were connected by wires to separate battery packs strapped to a user. For certain surveying applications, an automatic GPS antenna/receiver is mounted on the top end of a range pole and a user walks about with the range pole held in one hand. Automatically-collected data and operator-provided data are collected in a hand-held data collector unit which is sometimes conveniently mounted to a range pole. For improved accuracy, differential GPS systems use another radio receiver for receiving locally-broadcast error-correction signals. The other radio receiver for receiving the differential GPS correction signal is mounted to the top of a range pole.
The GPS receiver, the data collector, and the differential GPS receiver all operate on batteries which currently are self-contained or which are strapped to a user. A need has arisen for a light-weight range pole which can be combined with a rechargeable battery pack for use with equipment mounted on the range pole.